Telemetry generally refers to communication of data, instructions, and the like between a medical device and a medical device programmer. For example, the programmer may use telemetry to program a medical device to deliver a particular therapy to a patient. In addition, the programmer may use telemetry to interrogate the medical device. In particular, the programmer may obtain diagnostic data, event marker data, activity data and other data collected or identified by the medical device. The data may be used to program the medical device for delivery of new or modified therapies. In this manner, telemetry between a medical device and a programmer can be used to improve or enhance medical device therapy.
Telemetry typically involves wireless data transfer between a medical device and the programmer using radio frequency (RF) signals, infrared (IR) frequency signals, or other electromagnetic signals. Any of a variety of modulation techniques may be used to modulate data on a respective electromagnetic carrier wave. Alternatively, telemetry may be performed using wired connections, sound waves, or even the patient's flesh as the transmission medium. A number of different telemetry systems and techniques have been developed to facilitate the transfer of data between a medical device and the associated programmer.
Many implantable medical devices (IMDs) support telemetry. Examples of an IMD include implantable cardiac pacemakers, implantable defibrillators, implantable pacemaker/cardioverter/defibrillators, implantable muscular stimulus devices, implantable brain stimulators, other implantable organ stimulation devices, implantable drug delivery devices, implantable monitors, and the like. Telemetry, however, is not limited to communication with IMDs. For example, telemetry may also be used to communicate with non-implanted medical devices in substantially the same way as it is used with IMDs.
The evolution and advancement of telemetry has yielded a number of advances in the art including, for example, improved communication integrity, improved data transmission rates, improved communication security, and the like. Moreover, as new therapeutic techniques are developed, telemetry allows the new techniques to be programmed into older medical devices, including devices previously implanted in a patient. Unfortunately, the evolution of telemetry has also resulted in proliferation of a wide variety of different systems and communication techniques that generally require a unique programmer for communication with each type of device. Consequently, different types of medical devices, medical devices manufactured by different companies, or even similar medical devices manufactured by the same company, often employ different telemetry techniques. Accordingly, a wide variety of different programmers are needed to communicate with different medical devices in accordance with the different telemetry techniques employed by the medical devices.
A proposed solution to the large and diverse number of programmers required in a hospital and/or follow-up clinic environment to program, interrogate or follow patients with IMDs is a “universal programmer” as proposed, for example, by P Stirbys in “A Challenge: Development of a Universal Programmer”, PACE, Vol. 16, April 1993, pg 693–4 and by R Fortney, et al in “Activation Times for “Emergency Backup” Programs”, PACE, Vol. 19, April 1996, pg 465–71. As pointed out in these articles, the difficulty of implementing the required multiple up/down link formats for even a subset of the programmers currently in use and applying all the various formats in a single programmer is formidable.
Prior art programmers have included optimized and customized bandpass filters and demodulators for demodulating and detecting the telemetered data signal from an IMD from a particular manufacturer. It would be prohibitively expensive, large and complex to incorporate the required amplification, filtering and demodulation of all manufacturers' IMDs in a single programmer.
Although such typical present day programmers have performed generally effectively, they are considered to be unduly complex and bulky, requiring a lot of shelf space to store programmers from several manufacturers in a typical clinic. There is a need for an energy efficient programmer apparatus of this kind that is configurable to receive and demodulate data telemetered from a variety of implantable devices according to many different modulation schemes, with reduced complexity, size and cost. The present invention fulfills this need.